Concentrate solids



Jan. 23, 1951 J. E. CLELAND ETAL 2,538,898

METHOD FOR PRODUOING PROTEIN HYDROLYSIS PRODUCT Filed Oct. 15, 1948 60A/(ENTRA 7E SOL /05 soZ l ya BY um fl TTOR NE Y '.l i l This .invention relates. to aprocessbi." making a. 'addtion'fproduct A'in 'the treatment pf leather products and t o .th,e product so produced. object pf the invention istog provide a ;uocess for producing a product from protein whichcan be added to leather products to im= iiuoye` the properties of the leather. f Another object ofthe invention is to provide a product from protein which can ne added to 'leather products :to improve the properties ofthe feather. f

`f f-,Agiiother object of the invention is. to provide a process for producing a vproduct from protein which is soluble in aqueous solutions and which is precipitated from the aqueous solutions by or tanniqacid. Another object of the invention is to provide aproduct.. f rorn protein vvs rhicli ca n 1 be added to 'leather products in soluble form and then be madeiinsolublev 2;,Anotherobject of the invention gisto provide a. process for jproducing a slightly 'hydrolyzed proteinproduct which.: is adherentfto glass.

Another object of the inventionfis to provide l agprocess for producing. Va slightly vhydrolyzed protein product which is insoluble in water, but soluble in the lower alcohols, asfgsmethyl and cth-y1,- that have been diluted vslritljijy to 20% water vand'solublej in dilute aqueous solutions of ammonia or sodium carbonate and which Vis adherent to glass. -v

'These and other objects are attained by hyd'lyzing a purified glutenfwhichissubstantially 'free l from 'starch with lime vas a catalyst under I`s i ea .n i pressure, thenneutralizingzjand purifying the hydrolyzed product to remoy ej the undesirproducts introduced `during the hydrolyzing @beineutrlizinsfsteivsf. i f f `1 Th e ndi/ el vfeatures characteristic `oi this in' yention are s etfjfrth withpart ularity inthe appended claims, .The inventionitjself, however, 'jtha'stoits organization and itsfggmethod of op.; eifation'together wit'h Aadditionalobj ects and adir'tagesithreof, will best be the@following/,description ofi s u.ciiic embodi- -iient henxead 'in connection vgth theaccom pxying.. gs':which is a n `:sheet of the illustrated inthe drawing-:jme 'following steps-jare..,carried out on cq in-ercial-'gluten to-produce thelleather treating product rstood from PATENT I j l METHOD Fon PRoDUcINGrRoTEIN nYDRoLYsIs PRODUCT i .la'mesEdwn Cleland, Granite City, and Elmer ""'Henke, Collinsville, 111.," assgnors 'to Union H Starch & Refining-Company, Columbus, corporation of 4Indiana Application octobefialsiaseriamasaau Y f ''-4 oiaims. (01.260-1-12) rotein product which can. be employed as an Ind., a

. v2` l 1'- 2. Acid is added `tothe concentrated'prodict in suiiicient quantity to give it a pH-of 2 to 42 7 preferably about pH 2.1. The mix is thenh'ydrolyzed in an acid resistant converter ata steam 'pressure ofA 30 lbs. to 45 lbs. This product-"is neutralized to a pH of 4.5 with an'alkaline ma' terial such as caustic or lime and the product is iiltered and washed yto remove the solubilized starch conversion products, etc. ""3. Water and lime (CaO or `Ca '(OH)2) are added to the starch v'free product to give 'a pH of A9 to 13.5 preferably about pH 11.8 and this mix isv hydrolyzed at a'steam pressure of 25 lbs. to The hydrolyzed liquid product is then iiltered. The cake from this step is used as a component in animal feed". For the production of leather treating protein the hydrolysis is preferably conducted at lbs, steam pressure for one hour. 2A'

The lime hydrolysis gives amore uniform and selective hydrolysis of corn gluten than acids or strong alkalies. It is selective in dissolving and hydrolyzing the zein-like protein of c orn. This portion of the proteinmay at the same time be hydrolyzed to any degree desirable. This "type hydrolysis gives a water soluble protein at a pH of 4.5 or higher and retains Adesirable plastic properties. 'c A The use of alkalies as NaOH, KOH, and Na2CO3 for hydrolysisleaves slimy residues that g coat on the filter.` This makes iiltering very dii-j..

. give trouble in` thenext steps of. the process. With the use "of lime `these, diiculties are"el i 1 n I is'imprtant" for the 'following reasonsf 50 'l iions.

insured. .The lime hydrciysate alters easumand lime forms an insoluble 'soap with the' liberated 'fr ee fatty acid and i s easly filteredk out.v e lime"also.absorbs a large quantity vof thecarotinoids giving a lighter colored product.` 2

4.y Sulfur dioxide is bubbled through the ltrate from step 3 until thel pH of the liquor is reduced to a p H' of 7.3. Thev precipitated calcium sulte is filtered'oil! ,f .1.1 QTheremOVal of limby 'passingSOz gasthifougli a. Gives a crystalline precipitate.. that filters easily. b. Gives lower ash on finished product. (More complete re mo al .ofca lcium.) l

'"c'.' Eliminates scaling; oi eyaporator-tub gemessenemale d. It eliminates toxic and oiensive odors.

The removal of lime from the liquor by using sulfur dioxide gas gives a crystalline precipitate that is easily filtered. On the other hand the removalpy precipitating as sulphate or phos-v phate or "c oriilinatie'li' of the' twogives a slimy precipitate that stops the fiow'bf a lter.

The alkaline hydrolysis breaks up some of the sulphur proteins as methionine, cystine, etc., liberating CaS. On acidifying there is Has gaie liberated. This gas is toxic, corrosive te some metals and disagreeable smelling.4 The addition of the SO2 gas converts the calcium sulphide to calcium thiosulphate eliminating this problem.

5. The ltrate from step 4 is adjusted to a p-I of 7.0 to 4.@ preferably 6.5 with an acid, for example, sulfuric acid, and the product is Vacuum evaporated to 23'Be. This liquor is ltered. A

4 is washed free of hydrolyzed starch in a lter press. The cake in the press is air blown for a fewvv minutes to make the removal of the cake less dicult.

Three.. hundred sallonsniwater and- 150 lbs. of v'lime '(CawH-e) are added to converter.

lli/"ith the stirrerrunning'jthe starch-free gluten A from the lter press is added. The converter is Aitor heating for 1 hour the pressure is released.

The mixtureis iltered through a lter press and the presscake is washed with water. The filtrate plastioizer, for example,- lactc acid is added and 'obtaina pH of about 3.5 and the temperature of i the liquor is raised to lao The water layer is decarited from the tarry precipitate. This barry precipitate is dissolved in alcohols, preferably the lower numbers of vthe aliphatic series such as methyl, ethyl, etc. A plasticizer, such-as lactic acid, may be added to the solution. This solution lis then ready for coating glass/g If desired a dye may be'added to the solution.

The present invention is applicable to any vegetable or animal proteins of sufcient purity which are appreciably soluble in mild alkaline `solutions and may include protein or gluten from wheat, vKailii" corn, milo maize, soybeanss hide scraps, or corn (Zea Mays L). The gluten from "eorn is much preferred on the basis of economic considerations, yield, and properties, and particularly the nigh grade gluten 'as manufactured in the corn wet milling industry.

The plasticiaers which may be employed in the final protein product include any or vthe' knotn plastieizers lfor proteins such as lactic acid, propylene glycol, glycol esters, etc. following` examples illustrates how the process is carried out.

Example 1 'The corn gluten is obtained from the gluten discharge oi" the centrifuge used in the wet milling ofjcorn. The liquor is concentrated to 25% dry substance by filtration. More' dilute liquors 'work just aswell, however, more concentrated liqureliininates the handling of large Volumes. rIfhe mixture in the present example had 1270 lbs. @if dry substance with 47% yprotein?ll* 6.25) content.- The mixture is run into an acid n're stoten-t -fconverter* equipped "with a mechanical stirrer.4 The mixture is adjusted toa of 2.1 v"St-a'dilintg the required quantity or approximately 43 lbs. oi"5'0% H2504.

steam. This pressure is maintained l'rninutes Tnepressure-is then released 'and the mixture is neutralized with soda ash 'to a 'pH of' 4.5. This requiredlbs.'sodaash. l L

neutraiizedfmixture i'snltered-'andi the cake ilo Themixtureishea-ted toer-Ollas internal'pressure by injection of live l ensure Be. at 10Ea 'Sufficient lactic acid 'is addedt give a final product containing l'1/2% lactic cold on the dry substance basis. After the liquor coolsv to 9o F. a smallY quantity of hydrogen peroxide is added to improvethe oder about 150' cc. of '30% A'Hz'zl 1.'

dried. The'dried'product is' a'pale yellow powderof slight odor. 'It 'is soluble in aqueous solvents n avz ing a p'I- of 4.5 or more; It is' also soluble in 'aque Vous ammonium chloride 'or ammonium sulfate solutions. The powder contains 6.3% of wate; has an ash content of 2% and has a protcinfcentent of 80% estimated" on the nitrogen content N '6.25). i A water solution of the product'sf precipitated by tannic Aacid'at a'pH of' 5 or less. The tannic acid precipitate gives 'a plastic 'mass when-"heated to 80 C. The tannin precipitate' is' solublerv in ethyl-'alcohol or acetone. f'-

This product makes: a valuable additional product' to leather. It can be added to the leather in' a Ysoluble form' 'their4 made insoluble. fThis protein combines with 'theI tannin and" does' not changc'- v'the ash,l protein andv tannin ratio "of ltsatlriel".H n f Example 2 A corn gluten-1S Washed. and vthe starch is vref moved -by-acid hydrolysis 'a-S in Example'1 solid starch-free productie then dispersed in water and limeis added to. 'give the 'aux a. pH of 11.8. This mix is .hydrolvzedat 35 lbsqste'am pressure for 1/2 hour. The .resultant llquoris filtered andwashed and 'the 'nitrate and wash Water containing vlime and soluble proteinjare combined. .This combined liquor is treated with HClin .sufficient quantity to lgive apH of '3.5 'and the temperature. isgraised to 12o and-maintained 'at this temperature 'for 15 minutes. The liquor is allowed to settle, and the'water layeris decantedrrom the tarry precipitate. This tari@i precipitate' is dissolved in' denatured ethylalco heli-to produce" a-'solution' containing about' 36% solids. About 8.5% of lactic ,acidbasd on 'this' weight 'of the protein'is'added.'4

The product is yan alcohol solution' ora-slightly hydrolyzed coi-n protein. After spnatyi-ngr on 'glass it leaves a transparent lm that 'adheresto' 'glass on' .'dryiile". The pro'tctive-lm is" 'irisolblein t dissolves inA "dilut minimi dif-mlm "This material can then'be sodium carbonate solution. For example, it can be applied in conjunction with a dye for coating backs of photographical plates to prevent a halo effect. It is easily removed from the plate after exposure by washing in dilute sodium carbonate solution.

We claim:

1. In a process for manufacturing a light colored, plastic protein hydrolysis :product from vegetable proteins which contain no starch and no starch conversion products as impurities, the steps comprising, adding lime and Water to the protein to give a composition having a pH of 9-13.5, hydrolyzing the resultant composition under steam pressure of 25-45 pounds for from 1/3-21/2 hours, filtering the resultant composition, precipitating the alkaline earth metal ions introduced by said lime by babbling SO2 gas through the mix, ltering the product to eliminate undissolved protein and the precipitated compounds, and concentrating the resultant dissolved protein hydrolysate.

2. In a process for manufacturing a light colored, plastic protein hydrolysis product which is soluble in water and precipitatable from aqueous solutions by tannin or tannic acid from corn gluten which contains no starch and no starch conversion products as impurities, the steps comprising adding lime and water to said starch-free corn gluten to give a composition having a :pH of 9-13.5, hydrolyzing the resultant composition under steam pressure of 25-45 pounds, ltering the resultant composition, precipitating the alkaline earth metal ions introduced by said lime by bubbling SO2 gas through the mix, ltering the product to eliminate undissolved protein and the precipitated compounds, acidifying the filtrate to a pH of 7-4 and concentrating the resultant dissolved protein hydrolysate.

3. A process for manufacturing a light colored,

6 plastic lprotein hydrolysis product from corn gluten, said product being soluble in water and precpitatable from aqueous solution by tannin or tannic acid comprising the steps of freeing the gluten of starch, adding lime and water to give a composition having a pH of 11.8, hydrolyzing the resultant composition under steam pressure of 35 pounds for l hour, filtering the resultant composition, precipitating the alkaline earth metal ions introduced by said lime by bubbling SO2 gas through the mix, ltering the product to eliminate undissolved protein and the precipitated compounds, acidifying the filtrate to a pH of 6.5 and drying the resultant product.

4. A process -for manufacturing a light colored, plastic protein hydrolysis product from corn gluten comprising the steps of freeing the gluten of starch, adding lime and Water to give a composition having a pH of 11.8, hydrolyzing the resultant composition under steam pressure of 25-45 .pounds for 1/2 hour, ltering the resultant composition, acidifying the ltrate to a pH of 3.5 thereby producing a tarry precipitate, separating said precipitate and dissolving the protein of said tarry precipitate in alcohol.

JAMES EDWIN CLELAND. ELMER, HENKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,271,620 Brier et al. Feb. 3, 1942 2 324 951 Ratzer July 20, 1943 2,361,057 Ratzer Oct. 24, 1944 2,383,252 Huntzicker Aug. 21, 1945 2,397,307 Youtz Mar. 26, 1946 2,414,195 Evans et al Jan. 14, 1947 2,448,002 Pearce Aug. 24, 1948 

1. IN A PROCESS FOR MANUFACTURING A LIGHT COLORED, PLASTIC PROTEIN HYDROLYSIS PRODUCT FROM VEGETABLE PROTEINS WHICH CONTAIN NO STARCH AND NO STARCH CONVERSION PRODUCTS AS IMPURITIES, THE STEPS COMPRISING, ADDING LIME AND WATER TO THE PROTEIN TO GIVE A COMPOSITION HAVING A PH OF 9-13.5, HYDROLYZING THE RESULTANT COMPOSITION UNDER STEAM PRESSURE OF 25-45 POUNDS FOR FROM 1/3-2 1/2 HOURS, FILTERING THE RESULTANT COMPOSITION, PRECIPITATING THE ALKALINE EARTH METAL IONS INTRODUCED BY SAID LIME BY BUBBLING SO2 GAS THROUGH THE MIX, FILTERING THE PRODUCT TO ELIMINATE UNDISSOLVED PROTEIN AND THE PRECIPITATED COMPOUNDS, AND CONCENTRATING THE RESULTANT DISSOLVED PROTEIN HYDROLYSATE. 